Following two deadly crashes in Ethiopia and Indonesia, Boeing is confronting momentous problems with one of its newest and most critical aircraft models, the 737 Max 8.

Now that President Donald Trump and the Federal Aviation Administration have ordered that the US join a swath of countries in grounding the aircraft, it’s banned from flying passengers globally. The developments are a huge blow to Boeing, which has thousands of 737 Max orders on its books. Two crashes in five months is a troubling record for an airliner that entered service barely two years ago.

The causes of both crashes, which at this point appear to be similar, are still under investigation and the official reports won’t be published for months. Until then, here’s what we know:

What’s the current status of the Max 8?

Most operators quickly grounded their planes in the days following the second crash on Sunday. That list includes both Ethiopian Airlines and Lion Air, but also AeroMexico, Aerolíneas Argentinas, GOL Linhas Aéreas (Brazil), Turkish Airlines, S7 Airlines (Russia), FlyDubai, Air Italy, Cayman Airways, Norwegian, China Eastern Airlines, Fiji Airways and Royal Air Maroc.

More than 40 countries also banned the 737 Max from flying in their airspace. China (a huge Boeing customer and a fast-growing commercial aviation market) led the way and was joined by Indonesia, Thailand, Malaysia, Australia, India, Oman, the European Union and Singapore. Canada waited until early Wednesday morning but then reversed course.

Up until Wednesday, the FAA also declined to join the grounding order, saying in a statement tweeted on Tuesday that there is “no basis to order grounding the aircraft.” That was despite a public outcry from a group of senators and two flight attendant unions. But along with Trump’s order, the agency said it issued the order due to new evidence it collected and analyzed. The grounding will remain in effect pending further investigation.

Southwest and American have confirmed they will pull their 737 Max 8s from service and adjust their schedules to make up for the lost aircraft. The only other holdout, Panama’s Copa Airlines, has grounded its planes, as well. The order also affects the 737 Max 9, currently in service with United Airlines.

Older 737 models, like the 737-700, 737-800 and 737-900 don’t use the flight control system under investigation and aren’t affected by the grounding order.